Patent Application
20090236077
1. Field of the Invention
The present invention relates to a heat dissipation device, and more particularly to a heat dissipation device for dissipating heat generated by an electronic component.
2. Description of related art
A computer central processing unit (CPU) is the core controller of electrical signals in the contemporary personal computers. Continued development of the CPUs has enabled them to perform more and more functions. Heat generated by the CPUs has thus increased enormously. Such heat can adversely affect the operational stability of the computers. Measures must be taken to efficiently remove the heat from the CPU. Typically, a dissipation device having great heat conductivity is mounted on the CPU to remove the heat therefrom.
The conventional heat dissipation device commonly comprises a base thermally contacting with the CPU, a plurality of fins extending upwardly from a top of the base, and a fan mounted on a top portion of the heat sink. The fins are perpendicular to the base and parallel to each other with a predetermined distance; thus, a plurality of linear airflow passages is defined between the fins. When the heat dissipation device works, airflow generated by the fan blows spirally and downwardly into the airflow passages of the heat sink. The fins are so oriented that they have varied confronting angles with the airflow. Accordingly, a part of the fins cannot have a thorough contact with airflow, whereby heat in the part of the fins cannot be effectively taken away by the airflow flowing through the heat sink. Thus, heat dissipation efficiency of the heat dissipation device is not high and still needs to improve.
Thus, it is desired to devise a heat dissipating device which having a good heat dissipation efficiency.
A heat dissipation device for dissipating heat generated by an electronic component includes a base, a fin group and a heat pipe connecting the base with the fin group. The base thermally contacts with the electronic component. The fin group includes a plurality of fins located at a top of the base. The heat pipe includes an evaporating portion received in the base, a condensing portion extending spirally and upwardly from an end of the evaporating portion. The condensing portion of the heat pipe extends through the fin group. The fins of the fin group are arranged to have an arch-shaped profile. A fan is mounted over the fin group.
Other advantages and novel features will become more apparent from the following detailed description of preferred embodiments when taken in conjunction with the accompanying drawings, in which:
Many aspects of the present embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
Referring to
The heat sink assembly 10 comprises a base 12 contacting with the electronic component and a pair of heat sinks 19 located at a top of the base 12. Each heat sink 19 comprises a fin group 14, and a first heat pipe 16 and a second heat pipe 18 connecting the fin group 14 with the base 12.
The base 12 is located at a bottom of the fin groups 14 and spaced from the fin groups 14. The base 12 is substantially rectangular and made of metal with high degree of heat conductivity such as copper or aluminum. Four spaced grooves 124 are parallel to each other and defined in a bottom portion of the base 12 for receiving the first and second heat pipes 16, 18. A plurality of ribs (not labeled) extends from a top of the base 12. Two locking portions (not labeled) are formed at opposite sides of the base 12 for engaging with a pair of locking members 13. Each locking member 13 comprises a mounting plate (not shown) located below the locking portions of the base 12 and a pair of legs 132 extending outwardly from opposite ends of the mounting plate. Screws (not shown) extend through the mounting plates and engage with the locking portions of the base 12 to mount the locking members 13 on the base 12.
Referring to
Each fin group 14 comprises a plurality of vertical fins 140. The fins 140 are spaced from each other with a predetermined distance; thus a plurality of airflow passages (not labeled) is defined between every neighboring two of the fins 140. Each fin 140 is substantially rectangular and perforated with two through holes (not labeled) at a centre portion thereof. An outward corner of each fin 140 is bent to form a bent plate 148 for guiding airflow generated by the fan into the airflow passages of the fin group 14. A cutout 144 is defined in a lower portion of each fin 140 to receive the connecting portions 164, 184 of the first and second heat pipes 16, 18 of the other heat sink 19. Annular flanges 146 are formed during punching the through holes of the fins 14. The flanges 146 in each fin group 14 are soldered together to form a spiral-shaped channel (not labeled) along an anti-clockwise direction; thus, when the fins 140 of each fin group 14 are assembled together, two spiral channels (not labeled) are defined in the each fin group 14. The condensing portions 166, 186 of the first and second heat pipes 16, 18 are soldered in the channels, so that the first and second heat pipes 16, 18 and the fin group 14 are assembled together. The fins 140 of the fin group 14 are perpendicular to the condensing portions 160, 180 of the first and second heat pipes 16, 18.
The pair of heat sinks 19 are located at opposite sides of the base 12. The evaporating portions 160, 180 of the first and second heat pipes 16, 18 are received in the grooves 124 of the base 12 and coplanar with a bottom surface of the base 12 to contact with the electronic component. The connecting portions 164, 184 of the first and second heat pipes 16, 18 of one of the heat sinks 19 are opposite those of the other of the heat sinks 19. The connecting portions 164, 184 of the first and second heat pipes 16, 18 of the two heat sinks 19 are received in the cutouts 144 of the fin groups 14. The fin groups 14 each are formed with a substantially arch-shaped configuration. The fin groups 14 together form an annular configuration.
The fan holder 20 comprise four sleeves 22 each with a bottom portion abutting a corresponding leg 132 of the locking members 13, a pair of arc-shaped supporting plates 24 mounted on tops of the sleeves 22 and four elongated screws 26. The screws 26 extend through the supporting plates 24, the sleeves 22 and the legs 132 to threadedly engage with a fastening plate (not shown) under the printed circuit board thereby to mount the heat sink assembly 10 and the fan holder 20 on the printed circuit board. Opposite ends of each supporting plates 24 define mounting holes 240 respectively, whereby screws 50 can extend through the fan 30 to threadedly engage in the mounting holes 240 to thereby mount the fan 30 on the supporting plates 24.
The fan 30 has a circular configuration and comprises a cage (not labeled) and an impeller assembly (not labeled) received in the cage. Four mounting portions 35 extend outwardly from the cage of the fan 30, located corresponding to the opposite ends of the supporting plates 24. The screws 50 extend through the mounting portions 35 and engage into the mounting holes 240 of the supporting plates 24 to mount the fan 30 on the supporting plates 24.
In use, heat generated by the electronic component is absorbed by the base 12, then transferred to the fin group 14 via the first and second heat pipes 16, 18, and finally dispersed into ambient cool air. Airflow generated by the fan 30 spirally blows into airflow passages of the fin groups 14 along the anti-clockwise direction to dissipate heat generated by the electronic component. Due to the airflow passages of the fin groups 14 extending upwardly along the anti-clockwise direction and the airflow spirally blowing into the airflow passages along the anti-clockwise direction, the airflow generated by the fan 30 can easily blow into the airflow passages to have a thorough contact with all of the fins 140. Thus, heat dissipation efficiency of the heat dissipation device is improved. Furthermore, the bent plates 148 of the fin groups 14 extend outwardly from the fins 140; thus, the airflow generated by the fan 30 can more easily blow into the airflow passages by a guidance of the bent plates 148 to take away heat in the fins 140.
It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the invention.
